MDEV-16961 Assertion `!table || (!table->read_set ||...

MDEV-16961 Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed upon concurrent DELETE and DDL with virtual blob column

After iterating all fields and setting PART_INDIRECT_KEY_FLAG as
necessary, TABLE::mark_columns_used_by_virtual_fields() remembers
in TABLE_SHARE that this operation was done and need not be repeated.

But as the flag is set in TABLE_SHARE, PART_INDIRECT_KEY_FLAG must
be set in TABLE_SHARE::field[], not only in TABLE::field[].

Otherwise all new TABLEs opened from this TABLE_SHARE will
never have it.

mysql-test/suite/vcol/r/index.result

@@ -89,3 +89,13 @@ pk	left(c, 10)	length(c)	i
 1	bar bar ba	60000	11
 drop table t1;
 disconnect c1;
+CREATE TABLE t1 (b BLOB, vb TEXT AS (b) PERSISTENT, KEY(vb(64))) ENGINE=InnoDB;
+INSERT INTO t1 (b) VALUES ('foo');
+connect  con1,localhost,root,,test;
+CREATE TABLE t2 LIKE t1;
+connection default;
+DELETE FROM t1;
+connection con1;
+disconnect con1;
+connection default;
+DROP TABLE t1, t2;

mysql-test/suite/vcol/t/index.test

@@ -79,3 +79,19 @@ commit;
 select pk, left(c, 10), length(c), i from t1;
 drop table t1;
 disconnect c1;
+
+#
+# MDEV-16961 Assertion `!table || (!table->read_set || bitmap_is_set(table->read_set, field_index))' failed upon concurrent DELETE and DDL with virtual blob column
+#
+
+CREATE TABLE t1 (b BLOB, vb TEXT AS (b) PERSISTENT, KEY(vb(64))) ENGINE=InnoDB;
+INSERT INTO t1 (b) VALUES ('foo');
+--connect (con1,localhost,root,,test)
+--send CREATE TABLE t2 LIKE t1
+--connection default
+DELETE FROM t1;
+--connection con1
+--reap
+--disconnect con1
+--connection default
+DROP TABLE t1, t2;

sql/table.cc

@@ -6736,7 +6736,10 @@ void TABLE::mark_columns_used_by_virtual_fields(void)
     for (uint i= 0 ; i < s->fields ; i++)
     {
       if (bitmap_is_set(&tmp_set, i))
+      {
+        s->field[i]->flags|= PART_INDIRECT_KEY_FLAG;
         field[i]->flags|= PART_INDIRECT_KEY_FLAG;
+      }
     }
     bitmap_clear_all(&tmp_set);
   }